The man who was fatally shot under questioning about ties to a Boston marathon bombing suspect would have had trouble attacking officers because he was recovering from a knee injury, lawyers for his father said Tuesday.

Ibragim Todashev, 27, was killed in May while FBI agents and police from Massachusetts and Florida questioned him at his Orlando apartment about his friendship with suspected Boston Marathon bomber Tamerlan Tsarnaev.

Officials originally said the Chechen man lunged at an agent with a knife. They later said it was no longer clear what happened. An investigation is being led by the FBI.

At a news conference Tuesday, the lawyers said that a former detective they hired to investigate the death told them that all the agents in the room would have drawn their weapons and fired if they believed their lives were in danger - but based on their findings, they don't believe that happened.

"It was the FBI agent who shot all of the bullets," said Hassan Shibly, Tampa executive director of CAIR-Florida, a civil rights and legal organization. "If this were a survival shooting, typically all of the officers will draw their weapons."

FBI spokesman Paul Bresson said he couldn't comment on what was said at the news conference because the shooting investigation is ongoing.

But he referred to a statement that was issued by the FBI immediately after the shooting last May.

"The Special Agent, along with other law enforcement personnel, were interviewing an individual in connection with the Boston Marathon bombing investigation when a violent confrontation was initiated by the individual," the statement said. "The Special Agent, acting on the imminent threat posed by the individual, responded with deadly force. The individual was killed and the Special Agent was transported to the hospital with non-life threatening injuries."

Todashev's father, Abdulbaki Todashev, also spoke at the news conference, tearing up over his son. Todashev said he came to Florida from Chechnya last week to try to learn more about what happened. He brought to the news conference two posters with photos of his son, including a picture that showed Ibragim Todashev's stitched-up knee after surgery. The lawyers said the surgery was recent and that he was still limping at the time of questioning.

The lawyers noted that the FBI had questioned Todashev multiple times about how he knew the elder Boston marathon bombing suspect. The lawyers said the two knew each other because they trained at the same Boston-area gym.

They also said Todashev was supposed to go back to Chechnya for a visit several days before he was killed but delayed the trip to meet with FBI agents, who had promised it would be the last interview.

"My son was a very good boy," Abdulbaki Todashev said through a Russian translator. "He was a good grandson to his grandparents. He was a good brother. He was a good neighbor.

A maid who cleaned the home of former New England Patriots player Aaron Hernandez has testified at his murder trial that she saw him "messing with" the security camera in his basement the day after the killing.